JP4212215B2 - Surface treatment equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surface treatment apparatus suitable for various surface treatments on a substrate, particularly a film formation treatment on a substrate, and more particularly to a surface treatment apparatus capable of forming a crystalline thin film with high quality and high speed. Is.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, surface treatment apparatuses that perform surface treatments such as etching and film formation by applying high-frequency power to parallel plate electrodes to bring the reaction gas into a plasma state and decomposing it into chemically active ions and radicals are known. .
[0003]
For example, in a conventional parallel plate type plasma CVD (Chemical Vapor Deposition) apparatus for performing a film forming process, a pair of plate-like plasma generating electrodes are provided in parallel in a casing. One of the plasma generating electrodes also has a function as a substrate support, and the apparatus is further provided with a heater for adjusting the temperature of the substrate to a temperature suitable for vapor phase growth. . When electric power from a high-frequency power source (13.56 MHz power source) is applied between the two plasma generating electrodes while the substrate is placed on the one electrode, plasma is generated between these electrodes, For example, monosilane gas is activated and a silicon film is formed on the substrate surface.
[0004]
In such a conventional parallel plate type plasma CVD apparatus, a large area substrate is formed by a single film formation process by increasing the area of the flat plate-like plasma generating electrode on which the substrate is placed. Has the advantage of being able to However, in the conventional parallel plate type plasma CVD apparatus, the source gas converted into plasma by the two plasma generating electrodes is uniformly diffused into the film forming gas processing chamber, and a part thereof is placed on the electrode. It only contributes to the deposition of the substrate. For this reason, the utilization efficiency of the source gas is low. For example, when an amorphous silicon thin film or a crystalline silicon thin film is to be formed on a substrate, the film formation rate is about 1 to 2 liters / sec. The film formation speed is slow. For this reason, manufacturing a relatively thick semiconductor device such as a solar cell requires much longer time, which has been a main factor of low throughput and high cost.
[0005]
Therefore, it is conceivable to increase the input power from the high-frequency power source in order to increase the film forming speed. However, increasing the input power increases the energy of charged particles in the plasma. Damage caused by the collision of the charged particles having high energy with the substrate deteriorates the film quality. Furthermore, with the increase of the high frequency power from the high frequency power source, a large amount of fine powder is generated in the gas phase, and the deterioration of the film quality due to the fine powder is also drastically increased.
[0006]
Therefore, in the conventional parallel plate type plasma CVD apparatus, in order to avoid the damage caused by the collision of such high energy charged particles and the deterioration of the film quality due to the fine powder, the input power must be suppressed. That is, there is substantially an upper limit value of input power, and the film formation rate cannot be increased to a certain level or more.
[0007]
Further, in the etching apparatus using parallel plate type plasma, since the degradation of the processing quality due to the increase of the input power is smaller than that of the film forming process, the processing speed can be increased to some extent by increasing the input power. However, at present, further improvement in the processing speed is desired for the purpose of improving the quality of the etching process, improving the manufacturing efficiency, and reducing the manufacturing cost.
[0008]
On the other hand, a photovoltaic device forming device for a strip-shaped member, which is a traveling object to be processed, disclosed in Japanese Patent Application Laid-Open No. 11-145492 has a surface area in a discharge space of a high-frequency power application electrode (cathode electrode). Is larger than the surface area in the discharge space of the entire anode electrode including the belt-shaped member, and the potential of the cathode electrode when the glow discharge occurs is maintained at a positive potential of +30 V or more with respect to the grounded anode electrode including the belt-shaped member. ing. Furthermore, a plurality of threshold electrodes are installed on the cathode electrode in a direction perpendicular to the traveling direction of the belt-shaped member, and a discharge is caused between adjacent threshold electrodes. In this way, the cathode electrode is maintained at a positive potential of +30 V or more with respect to the band-shaped member and the anode electrode, and the above-described cathode electrode structure having the threshold-shaped electrode is used. It promotes excitation and decomposition reactions of material gases.
[0009]
It is considered that the photovoltaic device forming apparatus disclosed in the above-mentioned publication certainly improves the film formation rate by promoting the excitation and decomposition reaction of the material gas on the anode electrode side including the belt-shaped member. However, since glow discharge is also generated in the space between the belt-like member and the cathode electrode, damage due to collision of charged particles is unavoidable.
[0010]
Therefore, for example, a thin film forming apparatus disclosed in Japanese Patent Application Laid-Open No. 61-32417 is an activated gas comprising a definition chamber having a pair of opposed plasma generating electrodes in a vacuum chamber for forming a thin film on a substrate. A generator is arranged. A single pore for ejecting the activated gas into the vacuum chamber is formed in one wall portion of the activated gas generator. A substrate is supported in the vacuum chamber at a position facing the pores.
[0011]
In the thin film forming apparatus, a high frequency is applied to the pair of plasma generating electrodes.Electric powerIs applied to generate a glow discharge between both electrodes to create plasma. The source gas introduced into the activated gas generator is decomposed by this plasma. At this time, by adjusting the vacuum pump disposed in the vacuum chamber and the conductance of the pores, the vacuum degree of the vacuum chamber is lowered by two to three orders of magnitude lower than that of the activated gas generator, The converted source gas is ejected from the pores toward the substrate.
[0012]
A plasma generating electrode is arranged inside the activated gas generator defined in the vacuum chamber for forming a thin film in this way, and the source gas activated in the activated gas generator is actively directed toward the substrate. In the thin film forming apparatus to be sprayed, the deposition rate can be increased without increasing the input power. Furthermore, even when the input power is increased to generate stronger plasma, the plasma generating electrode is installed in the defined activated gas generator, and the substrate is generated by glow discharge between the electrodes. There is no risk of damage to Therefore, it is possible to further increase the deposition rate by increasing the input power. In addition, although the film formation rate is increased, crystallization of the thin film is also promoted, and a high-quality thin film can be formed at a higher film formation rate than conventional.
[0013]
[Problems to be solved by the invention]
Thus, although the film formation speed is increased by defining the plasma generation chamber and the film formation processing chamber, further improvement of the film formation speed is desired. High-speed deposition of microcrystalline thin films is strongly desired. In addition, because it is defined in two chambers, the internal structure of the surface treatment device becomes complicated, and a large vacuum pump is required to generate differential pressure in the two chambers. There is also a problem that soars.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a surface treatment apparatus capable of performing surface treatment at higher speed and higher quality and reducing production costs in order to achieve such a demand.
[0014]
[Means for solving the problems and effects]
  In order to solve this problem, the invention according to claim 1 is directed to generating plasma in the casing provided with plasma generating means, raw material gas inlet, and substrate support by the plasma generating means. A surface treatment apparatus for plasma-treating a substrate surface placed on the substrate support, between the plasma generation region having the plasma generation means and the substrate treatment region having the substrate support. Have one or more plasma outletsThe anode electrode is separated from the inner wall surface of the casing.At least one of saidAnode electrodeIs characterized by having one or more hollow discharge generation regions.
[0015]
  Further, in the invention according to claim 2, the plasma generating means, the raw material gas introduction port, and the substrate provided with the substrate support base, plasma is generated by the plasma generating means to convert the raw material gas into a plasma, and the substrate support A surface processing apparatus for plasma processing a substrate surface placed on a table, wherein one or more plasmas are provided between a plasma generation region provided with the plasma generating means and a substrate processing region provided with the substrate support. With outletThe anode electrode is separated from the inner wall surface of the casing.A hollow plasma generation electrode having one or more hollow discharge generation regions is arranged in the plasma generation region.
[0016]
  Further, the invention according to claim 3 of the present invention is that a plasma is generated by the plasma generating means in a casing having a plasma generating means, a raw material gas introduction port, and a substrate support, thereby converting the raw material gas into a plasma, thereby supporting the substrate. A surface treatment apparatus for plasma-treating a substrate surface placed on a table, wherein the casing is placed between a plasma generation region provided with the plasma generation means and a substrate treatment region provided with the substrate support. Has more plasma outletsThe anode electrode is separated from the inner wall surface of the casing.At least one of saidAnode electrodeIs characterized in that it has one or more hollow discharge generation regions, and a hollow plasma generation electrode having one or more hollow discharge generation regions is arranged in the plasma generation region.
[0017]
In the present invention, “hollow discharge” refers to a phenomenon in which plasma, particularly found in through holes, recesses, and cavities, is strongly generated and the density of plasma increases.
As the plasma generation means, discharge by a pair of plasma generation electrodes composed of a cathode and an anode, discharge having three or more electrodes, microwave discharge, capacitively coupled discharge, inductively coupled discharge, helicon wave discharge, PIG discharge, Means such as electron beam excited discharge can be employed.
[0018]
  4. The plate member interposed between the plasma generation region and the substrate processing region in the inventions according to claim 1 and 3.The anode electrodeThe hollow discharge generated in, HoLow anode discharge.
[0019]
  In additionWhen a pair of plasma generating electrodes consisting of a cathode and an anode is used as the plasma generating means, any one of the electrodesAlsoAdopt as a plate memberButit can.A plate member was used for the cathode electrodeIn some cases, the discharge generated in the hollow discharge generation region is a hollow cathode discharge.
  In the present specification, an electrode on the side to which main electric power for discharge is applied is a cathode electrode, and an electrode facing the cathode electrode is an anode electrode.
[0020]
  And in particular,Anode electrodeIt is preferable that the plasma outlet formed in the above is used as a hollow discharge generation region because the plasma introduced into the substrate processing region can be more effectively densified.
  In addition to the pair of plasma generating electrodes that are plasma generating means, a plate member may be interposed in two regions, and a plasma outlet may be formed in the plate member.
[0021]
In the inventions according to Claims 2 and 3, when a pair of plasma generating electrodes consisting of a cathode and an anode is adopted as the plasma generating means, at least one of the plasma generating electrodes is used as the hollow plasma generating electrode. Can also be used as Alternatively, the hollow plasma generation electrode can be arranged as a third electrode separately from the plasma generation electrode.
[0022]
In the surface treatment apparatus of the present invention as described above, a plate member may be interposed between the plasma generation region and the substrate treatment region in the casing, and it is necessary to completely define the two regions by the plate member. There is no. Therefore, the structure of the device is simplified, and the manufacturing cost of the device can be reduced.
[0023]
Furthermore, a required electric potential can be applied to the plate member, and a hollow discharge can be generated more efficiently in a hollow discharge generation region of the plate member, for example, a plasma outlet. Also, means for applying a required potential to the plate member can be easily installed.
[0024]
In particular, when a pair of plasma generating electrodes is employed as the plasma generating means and the plate member is used as one electrode of the plasma generating electrode, the plate member can be connected to and separated from the opposing electrode. Separating means can be provided. If the plate member can be brought into and out of contact with the opposing electrode in this way, the distance between the plate member and the opposing electrode, that is, between the plasma generating electrodes, for example, depending on applied power and other surface treatment conditions The distance can be adjusted appropriately. Thereby, the intensity of the discharge between the plasma generating electrodes can be adjusted, and the processing speed and processing quality can be controlled to a desired level.
[0025]
  In order to perform the surface treatment by the surface treatment apparatus, first, a raw material gas and a carrier gas are injected into the casing through the gas supply pipe, and plasma is generated in the plasma generation region by the plasma generation means. Here, in the surface treatment apparatus of the present invention, a gap between the plasma generation region and the substrate processing region.Anode electrodeHowever, each region is not defined so as to be completely partitioned as in the conventional apparatus. Thus, in the present invention, between the two regionsAnode electrodeHowever, since the two regions are not completely defined, the gas utilization efficiency is slightly lower than when the two regions are completely defined. Intervened in theAnode electrodeAs a result, the gas can remain in the plasma generation region, so that it can be converted to plasma with relatively high efficiency.
[0026]
  Plasma generated in the plasma generation region flows out from the plasma outlet to the substrate processing region due to the flow and diffusion of internal gas due to exhaust from the substrate processing region. At this time, by providing an appropriate gas flow rate and plasma parameters, the plasma in the plasma generation region is smoothly transported from the plasma outlet to the substrate processing region. Also, between the plasma generation region and the substrate processing regionAnode electrodeBy interposing, ion damage to the substrate due to plasma can be reduced.
[0027]
The source gas can be introduced until the plasma generated in the plasma generation region blows out to the substrate processing region and reaches the substrate surface. The activated source gas in the plasma reaches the substrate surface in the processing region by the plasma flow, and the substrate is subjected to surface treatment such as etching and film formation.
[0028]
  In the invention according to claim 1,Anode electrodeIt is important to generate a hollow discharge in one or more hollow discharge generation regions. By this hollow dischargeAnode electrodeSince plasma is newly generated in the hollow discharge generation region, the density of the plasma guided to the substrate processing region is increased.
[0029]
  In particular, saidAnode electrodeIf the plasma discharge port formed in is used as a hollow discharge generation region, the plasma generated in the plasma generation region is caused by an interaction such as a collision when passing through the plasma discharge port where the hollow discharge is generated. The energy of charged particles (electrons or ions) in the plasma is reduced. By reducing the energy of the electrons, the electrons are sufficient to generate neutral active species that contribute to the surface treatment from the source gas, and the ions that collide and damage the substrate surface are less likely to be generated. As a result, the number of neutral active species can be increased without increasing ions. Also, by reducing the number of high energy ions in the plasma, the effects of substrate damage due to these ions can be reduced.
[0030]
Thus, the hollow discharge increases the plasma density and neutral active species that contribute to the surface treatment, thereby increasing the surface treatment speed. Further, by reducing the energy of ions present in the plasma that collide with the substrate and cause damage, deterioration of the substrate surface can be suppressed, and high-quality surface treatment can be performed at high speed.
[0031]
In the invention according to claim 2, it is important to arrange a hollow plasma generating electrode in the plasma generating region. For example, when a pair of plasma generating electrodes consisting of an anode and a cathode is employed as the plasma generating means, at least one of them can be used as a hollow plasma generating electrode. That is, it is necessary that a hollow anode discharge is generated at the anode electrode, a hollow cathode electrode is generated at the cathode electrode, or a hollow discharge is generated at both electrodes. By generating the hollow discharge, plasma is newly generated in the hollow discharge generation region, so that the density of the plasma guided to the substrate processing region increases, and the active species contributing to the surface treatment increase. The speed of the surface treatment is further increased.
[0032]
  Further, in the invention according to claim 3, the hollow discharge and the hollow plasma generation electrode in the hollow discharge generation region of the plate member described above.The anode electrodeIt generates both a hollow discharge and Therefore, both the above-described effects of the hollow discharge at the plate member and the hollow discharge at the anode electrode are combined, and the speed and quality of the surface treatment are further improved.
[0033]
  Furthermore, not only the hollow discharge in the plate member, but also a hollow plasma generating electrodeThe anode electrodeAs a result of this hollow discharge, the following synergistic effects can be obtained in addition to the effects obtained by the respective discharges described above. That is, in addition to the hollow discharge in the plate member, the hollow discharge at the hollow plasma generating electrode occurs, so that the electron temperature in the hollow discharge region at the electrode is lowered and the electron density is increased. improves. Further, for example, when the cathode electrode is a hollow plasma generating electrode and a hollow discharge is generated at the cathode electrode, the high frequency voltage at the cathode electrode is decreased and the self-bias voltage is increased. The space potential of the plasma also increases. As a result, hollow discharge easily occurs in the plate member, and high-density plasma can be generated in the plate member. Further, for the same reason, electric field concentration is likely to occur in the plasma generation region, and it is possible to generate non-uniform discharge that has been made into high-density plasma locally.
[0034]
As the electrode material of the hollow plasma generating electrode, and when using a pair of plasma generating electrodes as the plasma generating means, in addition to SUS, Al, etc., Ni, Si, Mo, W, etc. are used as the electrode material. Can be adopted. When an electrode material having a large secondary ion emission coefficient due to ion bombardment from the plasma is used, the plasma becomes denser and the processing speed is improved. In particular, in the case of a surface treatment apparatus that performs silicon film formation, when Si is used as an electrode material, the electrode itself functions as a thin film material supply source, so that the film formation speed is improved and Stability is also increased. Furthermore, if boron or phosphorus is doped in advance on the electrode made of Si, the thin film can be automatically doped, which is particularly advantageous when a very small amount of doping is performed.
[0035]
As the substrate, glass, organic film, or metal such as SUS can be used. Furthermore, the surface treatment apparatus of the present invention can be used for various surface treatments such as film formation, ashing, etching, ion doping, etc., but a silicon thin film or an oxide film such as amorphous silicon or crystalline silicon is formed on the surface of the substrate. When used, it is particularly preferably used.
[0036]
When providing a large number of the plasma outlets, a uniform thin film can be formed at a high speed even on a large area substrate, particularly if all the outlets are used as a hollow discharge generation area to cause hollow discharge. This is preferable because it is possible.
[0037]
The source gas introduction port may be opened in the plasma generation region, or only a carrier gas is introduced into the plasma generation region, and the source gas introduction port may be opened on a side surface of the plasma outlet. it can. Further, for example, by using an introduction means such as a pipe for introducing a source gas, the source gas inlet is opened in the substrate processing region, and the source gas is introduced between the plasma outlet and the substrate in the substrate processing region. May be. When the source gas inlet is opened at the outlet or when the source gas inlet is opened at the substrate processing region, the source gas is converted into plasma by the plasma carrier gas passing through the outlet. In this case, the inner wall surface of the plasma generation region is not contaminated by the source gas.
[0038]
The plasma generating electrode can be connected to a direct current power source or a high frequency power source and applied from a direct current to a high frequency power, but it is particularly preferable to apply the high frequency power. Furthermore, a bias can be applied to the cathode electrode and the anode electrode by a DC or AC power source or a pulse generating power source, respectively.
[0039]
In order to generate hollow discharge at the plasma outlet, in the invention according to claim 4, the opening width W (1) of the minimum part of at least one of the plasma outlets is set to W (1) ≦ 5L (e) Or, it is set in a range satisfying either W (1) ≦ 20X. However, L (e) is the atom or molecular species having the smallest diameter among the source gas species and the electrically neutral atoms and molecular species (active species) generated by decomposition under the desired plasma generation conditions. X) is the thickness of the sheath layer generated under the desired plasma generation conditions. In addition, the opening width W (1) of the minimum portion of at least one of the plasma outlets satisfies a range satisfying X / 20 ≦ W (1), and further satisfies X / 5 ≦ W (1). It is preferable to set the range.
[0040]
The mean free path of electrons in the scattering of electrons and gas molecules (including atoms) depends on the gas pressure, the scattering cross section of atoms and molecules, and the temperature. The plasma generation conditions include these gas pressures, Includes scattering cross sections of atoms and molecules, temperature, etc.
[0041]
By setting the opening width W (1) of the plasma outlet in the above range, hollow discharge can be effectively generated at the plasma outlet and plasma can be efficiently blown out from the outlet. Can do.
[0042]
In the present invention, the opening width W (1) of the plasma outlet is the diameter when the opening shape of the plasma outlet is circular, and the length of the short side when the shape is rectangular or slit. Dimensions. That is, the shortest dimension in the opening shape is the opening width W (1).
[0043]
As the shape of the plasma outlet, it is possible to adopt a shape capable of actively drawing the plasma in the plasma generation region into the outlet and diffusing the plasma at a desired angle in the substrate processing region. For example, a cylindrical shape with a circular cross section, a truncated cone shape that expands from the plasma generation region to the substrate processing region, and a combination thereof, and further, a substantially half of the upstream side is reduced in diameter toward the downstream side, and the downstream side Examples include a shape in which the half of the side expands toward the downstream side. Furthermore, as described above, the cross section may be a rectangular column shape or a slit shape.
[0044]
When surface treatment is performed over a wide area of the substrate, for example, a plurality of circular plasma outlets can be formed in a required pattern. Alternatively, it may be a substantially continuous long slit shape that can be drawn with a single stroke, specifically a spiral shape or a meandering shape.
[0045]
According to the fifth aspect of the present invention, the hollow plasma generating electrode has one or more recesses on the surface facing the plasma generated by the plasma generating means, and at least one of the recesses generates a hollow discharge. It is considered as an area.
According to the invention of claim 6, the hollow plasma generating electrode is a hollow body, and the electrode communicates with the plasma generated by the plasma generating means at one or more through holes communicating with the inside of the cavity. And at least one of the through-holes is a hollow discharge generation region.
[0046]
Thus, a recess is formed in the hollow plasma generating electrode, or a through hole communicating with the hollow plasma generating electrode as a hollow body is formed, and the recess or the through hole is defined as a hollow discharge generation region. By doing so, the surface area of the hollow plasma generating electrode that is substantially in contact with the plasma is increased. For example, when the cathode electrode is a hollow plasma generating electrode and a cathode discharge region is formed on the cathode electrode, the cathode electrode potential (self-bias) at the time of glow discharge generation can be taken in the positive direction, The consumption of input power in the vicinity of the anode electrode, that is, the excitation and decomposition reaction of the raw material gas can be promoted, and the surface treatment speed can be improved.
[0047]
Such control of the self-bias leads to control of the plasma space potential, and the magnitude of damage caused by the collision of ions with the substrate can be adjusted intentionally. Therefore, for example, when a film forming process is performed, the crystallinity of the crystalline thin film can be controlled.
[0048]
In order to effectively generate hollow discharge in the recess or the through hole, in the invention according to claim 7, the opening width W (2) of the minimum portion in the recess or the through hole is set to W (2) ≦ The range is set to satisfy either 5L (e) or W (2) ≦ 20X. However, L (e) is the atom or molecular species having the smallest diameter among the source gas species and the electrically neutral atoms and molecular species (active species) generated by decomposition under the desired plasma generation conditions. X) is the thickness of the sheath layer generated under the desired plasma generation conditions.
[0049]
The cross-sectional shape of the recess or the through hole can be a circle or a polygon, and the shortest dimension in the opening shape is the opening width W (2). Further, the opening width W (2) of the minimum portion of at least one of the plasma outlets satisfies the range satisfying X / 20 ≦ W (2), and further satisfies X / 5 ≦ W (2). It is preferable to set the range.
[0050]
According to the eighth aspect of the present invention, the hollow plasma generating electrode is a hollow body, and the electrode has one or more through holes communicating with the inside of the cavity at a portion facing the plasma generated by the plasma generating means. Thus, at least a part of the inside of the cavity is a hollow discharge generation region.
In this way, by generating hollow discharge in at least a part of the inside of the cavity, the plasma density can be further increased, so that the excitation and decomposition reactions of the source gas are remarkably promoted and the surface treatment speed is improved. Further, when the hollow plasma generating electrode is a cathode electrode, the self-bias can be further controlled to a positive potential by increasing the surface area of the cathode electrode in contact with the plasma. The decomposition reaction is further promoted and the surface treatment speed is significantly improved.
[0051]
In addition, for an apparatus that performs surface treatment that does not adversely affect the collision of ions with the substrate, such as etching, ashing, or ion doping, the hollow plasma generating electrode is constituted by an anode electrode, and the inner wall surface of the anode electrode is formed. A substrate support may be used, and the inside of the anode electrode may be the substrate processing region. In this case, the entire substrate processing region is surrounded by the anode electrode, so that the substrate processing region and the plasma generation region are substantially defined.
[0052]
The substrate is directly exposed to the hollow anode discharge, and the processing speed such as etching, ashing, and ion doping is improved. However, in such a surface processing apparatus in which the inside of the anode electrode is a substrate processing region defined as a plasma generation region, the collision damage of ions to the substrate is large, so it is somewhat unsuitable for film formation processing. .
[0053]
Further, the hollow plasma generating electrode made of a hollow body is preferably provided with one or more partition walls extending in the height direction inside the cavity in order to increase the surface area thereof. That is, it is preferable that the hollow plasma generating electrode has a plurality of cavities defined by the partition walls. In this case, it is necessary to form at least one through hole for each defined region.
[0054]
In order to efficiently generate hollow discharge inside the cavity of the hollow plasma generating electrode, according to the invention according to claim 9, at least one of the inside of the cavity along the through hole formation direction of the hollow plasma generating electrode. The facing distance H at the part is set to a range satisfying either H ≦ 5L (e) or H ≦ 20X. However, L (e) is the atom or molecular species having the smallest diameter among the source gas species and the electrically neutral atoms and molecular species (active species) generated by decomposition under the desired plasma generation conditions. X) is the thickness of the sheath layer generated under the desired plasma generation conditions. The facing distance H inside the cavity along the formation direction of the through hole of the hollow plasma generating electrode that is a hollow body is a range that satisfies X / 20 ≦ H, and also a range that satisfies X / 5 ≦ H. It is preferable to set to.
[0055]
According to the tenth aspect of the present invention, a magnetic field is formed in the vicinity of the plasma outlet and / or in the vicinity of the recess, the through hole, and / or in the cavity. Here, “near” includes the inside of the plasma outlet, the recess, and the through hole, and the peripheral edge of the opening, the recess, and the through hole. Further, it is preferable that the magnet be arranged so that the magnetic field lines of the magnetic field are parallel to the axial direction of the plasma outlet, the concave portion, and the through hole, and parallel to the electrode surface inside the cavity.
[0056]
The strength of the magnetic field is preferably 1 to 2000 mT, more preferably 5 to 500 mT in the plasma outlet, the recess, the center of the through hole, or the inside of the cavity. In addition, the strength of the magnetic field is preferably 2 to 2000 mT, more preferably 5 to 1000 mT at the plasma outlet and / or the recess, the inner wall surface of the through hole and the vicinity thereof, or the vicinity of the cavity inner wall portion. .
[0057]
By arranging the magnetic field in this way, the trajectory of electrons is adjusted, and in or near the plasma outlet where the hollow discharge occurs, or the recess or the through hole where the hollow cathode discharge or the hollow anode discharge occurs. Thus, electrons can stay in the vicinity and the vicinity thereof, or inside the cavity for a long time, and the generation of active species contributing to the surface treatment is promoted. Therefore, the surface treatment speed is further improved. In addition, since there is no change in the energy of electrons due to this magnetic field, high-quality surface treatment can be maintained without generating ions that have an adverse effect due to the increase in electron energy.
[0058]
Furthermore, according to the eleventh aspect of the present invention, there is provided a potential applying means for applying a desired potential to the substrate. For example, the potential application means can apply the same potential to the substrate by applying a desired potential to the substrate support on which the substrate is placed. The same potential applying means includes means for monitoring the potential Vs of the process plasma reaching the substrate and the potential of the substrate, if necessary. The potential Vs of the process plasma is determined by the potential of the electrode with which most of the plasma is in contact. Therefore, for example, the potential Vs of the process plasma can be monitored by monitoring the high-frequency voltage of the plasma generating electrode or the like and the self-bias.
[0059]
For example, when a film formation process is performed on a substrate, in order to suppress ion damage from plasma, it is desirable to reduce the voltage difference between the substrate and the process plasma potential Vs, which is substantially the same as the plasma potential Vs. It is more preferable to apply this potential. The potential applied to the substrate in the film formation process is preferably in the range of 1/2 to 1 times the potential Vs of the process plasma. For example, in the case of performing an etching treatment, anisotropy can be improved by applying a potential lower than the plasma potential Vs, particularly a negative voltage.
[0060]
In this way, by applying a desired potential to the substrate and intentionally controlling the voltage difference between the substrate and the plasma, plasma damage can be reduced without reducing the processing speed in the case of film formation. In addition, in the case of an etching process, the etching shape such as anisotropy can be controlled.
[0061]
Moreover, it is preferable to make a nozzle body project at the opening edge of at least one side of the plasma outlet and / or the recess and the through hole. The nozzle body may have its center line aligned with the axial direction of the plasma outlet and / or the recess and the through hole, or the center line of the nozzle body may be coaxial with the plasma outlet and / or the recess and the through hole. You may arrange | position with an angle with respect to a line direction. The shape of the nozzle body may be a cylinder having a constant cross-sectional shape or a cylinder that gradually decreases or increases the cross-sectional dimension. Furthermore, a tubular nozzle body may be arranged in a spiral shape.
[0062]
By projecting the nozzle body in the plasma blowout port and / or the recess and through hole, the thickness of the member where the plasma blowout port is formed and the hollow plasma generating electrode may be increased unnecessarily. The length of the plasma outlet and / or recess and through-hole can be freely set, and if the length is increased, the area of occurrence of hollow discharge at the plasma outlet and / or recess and through-hole is expanded. Therefore, the plasma density is increased and the surface treatment speed is improved.
[0063]
Furthermore, it is preferable that the nozzle length of the nozzle body is indefinite. That is, it is not necessary for all the nozzle bodies to have a uniform length in the plasma outlet and / or the recess, or the plasma outlet and / or the through hole, and the nozzle body can be appropriately changed. Thus, by changing the length of the nozzle body, the intensity of the plasma reaching the substrate can be made uniform over the entire surface of the substrate.
[0064]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings and preferred examples.
  FIG. 1 is a schematic view of a surface treatment apparatus 1 according to a first embodiment of the present invention. In the apparatus 1, a casing 2 that shields from outside air is grounded. Inside the casing 2, two regions, a plasma generation region 3 and a substrate processing region 4, are formed vertically, and a horizontal region made of an electrode material is formed between these regions.Anode electrode 6Is intervening.
[0065]
  In the plasma generation region 3, an electrode member 5 is provided on the upper wall 2 a formed by the insulator of the casing 2.Anode electrode 6It is attached in parallel. The electrode member 5 is connected to a high frequency power source P, and is disposed in parallel to face the electrode member 5.Anode electrode 6Is grounded. By applying electric power to the electrode member 5, the electrode member 5 andAnode electrode 6Discharge occurs between the two and plasma is generated. That is, the electrode member 5 isIt is a cathode electrode which comprises a plasma generating electrode.
[0066]
  In the present invention, as described above,Anode electrode 6Are separated from the inner wall surface of the casing 2 without being in close contact with each other, and are installed in the casing 2 by appropriate means, for example, a support member from the floor surface of the casing 2. Therefore, saidAnode electrode6 is easy to install, and the manufacturing cost of the apparatus can be reduced. In this embodiment, the sameAnode electrode 6Is grounded.Anode electrode 6Is grounded independently from the casing 2, soAnode electrode 6It is also possible to apply a desired bias. Furthermore,Anode electrode 6It is also possible to change the distance to the cathode electrode 5 by moving the position up and down. By changing the distance between the anode electrode 6 and the cathode electrode 5, the discharge intensity between the two can be adjusted according to the processing conditions such as applied power, and the processing speed and processing quality can be controlled.
[0067]
  The interposition between the plasma generation region 3 and the substrate processing region 4Anode electrode 6A circular through-hole 7 is formed in the center of the plasma, and the through-hole 7 constitutes the plasma outlet 7 of the present invention.The
[0068]
In this embodiment, the cross-sectional shape of the plasma outlet 7 is circular. However, for example, a rectangular shape, or a truncated cone shape whose diameter increases from the plasma generation region 3 toward the substrate processing region 4, Further, it is possible to adopt a truncated pyramid shape, or a shape in which a substantially half part on the upstream side is reduced in diameter toward the downstream side and a half part on the downstream side is increased in diameter toward the downstream side. Further, the plasma outlet 7 can be formed into a slit shape.
[0069]
The opening width W, that is, the diameter W of the plasma outlet 7 is set in a range satisfying either W ≦ 5L (e) or W ≦ 20X. However, L (e) is the atom or molecular species having the smallest diameter among the source gas species and the electrically neutral atoms and molecular species (active species) generated by decomposition under the desired plasma generation conditions. X) is the thickness of the sheath layer generated under the desired plasma generation conditions. By setting to such a range, the plasma outlet 7 can be set as a generation region of a hollow anode discharge. The opening width W is preferably set in a range of X / 20 ≦ W, and further, the opening width W is preferably set in a range of X / 5 ≦ W.
[0070]
Further, the dimension T in the length direction (thickness direction) of the plasma outlet 7 has a lower limit of about X / 50. The upper limit is determined by restrictions on the size of the apparatus, that is, the thickness of the anode electrode 6. The length T of the plasma outlet 7 is preferably 0.1 mm to 100 mm in the case of the gas pressure and diameter described above. From the viewpoint of efficiently generating a hollow discharge, it is advantageous that the length T of the plasma outlet 7 is large, and a stronger plasma can be generated. Therefore, a substantial length T of the plasma outlet 7 can be increased by attaching a nozzle body to the opening edge of the plasma outlet 7.
[0071]
In this embodiment, a gas supply port 8 is formed through the upper wall 2a of the casing 2 and the cathode electrode 5, and a film forming process is performed from the gas supply port 8 into the plasma generation region 3. In some cases, for example, a mixed gas of a source gas such as monosilane and a carrier gas for promoting the generation of plasma and stabilizing the plasma and transporting the source gas to the substrate S is introduced. The gas supply port 8 is not limited to a cylindrical shape, and may be a rectangular tube shape.
[0072]
Furthermore, the formation position of the gas supply port 8 is not limited to the above position, and can be formed at an arbitrary position. For example, as shown in FIG. 2, it may be formed at a position opening at the bottom of the recess 5 a, or may be formed at a position opening at the peripheral wall of the anode electrode 6. Also, a plurality of the gas supply ports 8 can be formed.
[0073]
Note that only the carrier gas is introduced into the plasma generation region 3 from the gas supply port 8, and a different introduction port is provided for the source gas separately to provide the plasma generation region 3, the film forming region 4, or the plasma outlet. 7 can also be introduced.
[0074]
A substrate support 9 is arranged in the substrate processing region 4 at a position facing the plasma outlet 7. In this embodiment, since the substrate support 9 is grounded, the substrate S placed on the support 9 is similarly grounded. The substrate support 9, that is, the substrate S, can be biased in a direct or alternating manner without being grounded, or can be biased in a pulse manner. Alternatively, the substrate S can be electrically insulated from the substrate support 9. The substrate support 9 has a built-in heater, and the temperature of the substrate S placed on the upper surface of the substrate support 9 is adjusted to a temperature suitable for vapor phase growth.
[0075]
When a film forming process is performed by the surface treatment apparatus 1, if a high frequency power is applied to the cathode electrode 5 by a high frequency power source P, a discharge occurs between the electrodes 5 and 6, and plasma is generated in the plasma generation region 3. To do. The plasma activates the source gas and the carrier gas introduced into the plasma generation region 3 to generate active species that contribute to film formation. At this time, the plasma in the plasma generation region 3 flows out from the plasma outlet 7 into the substrate processing region 4 due to the flow of internal gas accompanying the exhaust from the substrate processing region 4 and further diffusion. The surface of the substrate S in the processing region 4 is plasma-processed by the plasma flow, and a thin film is formed on the surface of the substrate 4.
[0076]
At this time, in the present invention, by setting the opening width W of the plasma outlet 7 within the above range, a hollow anode discharge is generated at the plasma outlet 7. Due to this hollow anode discharge, a new plasma is generated at the plasma outlet 7, so that the density of the plasma guided to the substrate processing region 4 is increased. Furthermore, when the plasma generated in the plasma generation region 3 passes through the plasma outlet 7 which is the generation region of the hollow anode discharge, the energy of electrons in the plasma is sufficient to generate active species, Therefore, the plasma introduced to the substrate processing region 4 further increases the number of active species contributing to the film formation, resulting in a plasma with a high density, and the film formation rate is remarkably high. improves. Furthermore, since the ion energy in the plasma also decreases when passing through the plasma outlet 7 where hollow anode discharge is generated, the plasma guided to the substrate processing region 4 collides with the substrate. There are few ions that cause damage, and high-quality film formation is possible.
[0077]
As described above, in the present embodiment, the substrate support 9, that is, the substrate S is grounded. However, a desired potential can be applied without grounding the substrate S. In the film formation process, a potential that is 1/2 to 1 times the potential Vs of the process plasma that reaches the substrate S is applied to the substrate S to reduce the voltage difference between the substrate and the process plasma. It is possible to form a high-quality thin film by reducing ion damage from plasma.
[0078]
At this time, the potential Vs of the process plasma is determined by the potential of the electrode with which most of the plasma is in contact. Therefore, for example, the potential Vs of the process plasma can be monitored by monitoring a high-frequency voltage such as a cathode electrode and a self-bias.
[0079]
Furthermore, in this embodiment, a single plasma outlet 7 having a circular cross section is formed. However, when surface treatment is performed over a wide area of the substrate S, the plasma outlet 7 is, for example, shown in FIGS. A plurality of them can be formed in the arrangement as shown in FIG. The arrangement based on the regular hexagon shown in FIG. 17A, the arrangement based on the quadrangle shown in FIG. 17B, the arrangement based on the triangle shown in FIG. Furthermore, as shown in FIGS. 18A to 18C, in these arrangements, an arrangement in which a plasma outlet is not formed at the central portion is more preferable. Moreover, it is also preferable to set it as the arrangement | positioning except the radial form shown to Fig.19 (a) and FIG.19 (b), and the center part shown to Fig.20 (a) and FIG.20 (b).
[0080]
Furthermore, if a substantially continuous slit shape that can be drawn with one stroke, for example, a spiral shape or a meandering shape as shown in FIG. 21, a uniform process can be performed over a large area. In addition, it is preferable to set the hole diameter and the slit width W within the scope of the present invention, both in the case of a plurality of holes and in the shape of a slit. However, the plurality of holes do not need to have a constant hole diameter, and the slit width does not need to be constant in the length direction. In order to generate a hollow anode discharge uniformly, it is desirable to gradually reduce or gradually increase the size of the hole diameter and the slit width from the central portion of the anode electrode to the outer edge portion according to various conditions.
[0081]
  In the above embodiment, the aboveAnode electrode 6The electrodes 5 and 6 can be biased by a DC or AC power source or a pulse power source, respectively. At this time, the present inventionAnode electrode 6Is not in close contact with the inner wall surface of the casing 2 and is installed independently of the casing by, for example, a support member from the floor surface.Anode electrode 6Application of a bias to is easy.
[0082]
In this embodiment, since the internal gas is exhausted from the substrate processing region 4, a flow of internal gas from the plasma generation region 3 to the substrate processing region 4 is formed in the surface processing apparatus. However, the present invention is not limited to this. An internal gas exhaust port may be provided in the plasma generation region to reverse the flow of the internal gas. However, in this case, since the plasma is transported from the plasma generation region 3 to the substrate processing region 4 only by diffusion and plasma transport due to the flow of the internal gas cannot be expected, the surface treatment speed is slightly reduced. As a result, high-speed processing is ensured. Gas can be introduced at any position of the casing. In particular, when a gas is introduced from the substrate processing region 4, it is easy to obtain a diffusion effect.
[0083]
Furthermore, even when other surface treatments such as ashing, etching, ion doping and the like are performed using the above-described apparatus, the surface treatment can be performed at a lower temperature and at a higher speed than in the past. For example, when an etching process is performed, anisotropy can be improved by applying a potential lower than the potential Vs of the process plasma, particularly a negative voltage, to the substrate S.
[0084]
Hereinafter, another embodiment of the present invention will be specifically described with reference to the drawings. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
[0085]
FIG. 2 is a schematic view of a surface treatment apparatus 20 according to a second embodiment of the present invention. This example has the same configuration as that of Example 1 except that the cathode electrode is different.
In the second embodiment, the cathode electrode 10 constitutes the hollow plasma generating electrode of the present invention. That is, a plurality of concave portions 10 a having a circular cross section are formed on the surface of the cathode electrode 10 facing the anode electrode 6. The opening width W of the concave portion 10a, that is, the diameter W is set in a range satisfying either W ≦ 5L (e) or W ≦ 20X. However, L (e) is the atom or molecular species having the smallest diameter among the source gas species and the electrically neutral atoms and molecular species (active species) generated by decomposition under the desired plasma generation conditions. X) is the thickness of the sheath layer generated under the desired plasma generation conditions.
[0086]
The opening width W is preferably set in a range of X / 20 ≦ W, and further, the opening width W is preferably set in a range of X / 5 ≦ W. When the gas pressure is in the range of 10 to 1400 Pa among the plasma generation conditions, the diameter of the recess 10a is set in the range of 0.1 to 100 mm, more preferably 1 to 20 mm. By setting the diameter of the concave portion 10a within such a range, the concave portion 10a can be set as a hollow cathode discharge generation region.
[0087]
The plurality of recesses 10a are preferably formed in an arrangement as shown in FIGS. The arrangement based on the regular hexagon shown in FIG. 17A, the arrangement based on the quadrangle shown in FIG. 17B, the arrangement based on the triangle shown in FIG. Furthermore, as shown in FIGS. 18A to 18C, in these arrangements, an arrangement in which the concave portion 10a is not formed in the central portion, that is, the position directly above the plasma outlet 7 is further preferable. Moreover, it is also preferable to set it as the arrangement | positioning except the radial form shown to Fig.19 (a) and FIG.19 (b), and the center part shown to Fig.20 (a) and FIG.20 (b).
[0088]
The depth D of the concave portion 10a is generally set to have a lower limit of X / 50. The upper limit is determined by restrictions on the size of the apparatus, that is, the thickness of the cathode electrode 10. The depth D of the recess 10a is preferably 0.1 mm to 100 mm in the case of the gas pressure and diameter described above. From the viewpoint of efficiently generating a hollow discharge, it is advantageous that the depth D of the concave portion 10a is large, and a stronger plasma can be generated. Therefore, a nozzle body can be attached to the opening edge of the recess 5a to increase the substantial depth D of the recess 10a.
[0089]
In the present embodiment, the recess 10a has a circular cross section, but may have a polygonal shape. The cross-sectional area may not be constant, and the cross-sectional area may be changed in the axial direction. For example, the bottom surface may be a concave portion larger or smaller than the opening. Furthermore, the concave portion 10a may have a rectangular or groove structure such as a spiral shape or a meandering shape as shown in FIG. In the case of such a rectangular or spiral groove structure, the opening width W of the recess 10a is a groove width (a dimension between groove walls), and the groove width is set within the above-described range. . The groove width may not be constant, and the groove width can be gradually decreased or gradually increased from the center of the cathode electrode 10 toward the outer edge. Moreover, you may form a partial unevenness | corrugation in the inner wall face of the said recessed part 10a. The plurality of recesses 10a do not have to have the same size and form, and a plurality of recesses 10a having different sizes and forms may be formed.
[0090]
At this time, the cathode electrode 10 is formed with a plurality of recesses 10a, and the opening width W of the recesses 10a is set within the above-mentioned range, so that a normal glow discharge is performed according to the applied high frequency power. To discharge including hollow cathode discharge. Hollow cathode discharge is generated in the recess 10a, and new plasma is generated in the recess 10a. Therefore, the plasma generated in the plasma generation region 3 becomes a high-density plasma, and the number of active species contributing to the film forming process increases, so that the surface treatment speed is increased. Further, by forming the concave portion 10a in the cathode electrode 10, the surface area of the cathode electrode 10 that is substantially in contact with plasma is increased. As a result, the self-bias at the time of discharge generation can be taken in a more positive direction, the excitation and decomposition reaction of the source gas in the vicinity of the grounded anode electrode 6 is promoted, and the surface treatment speed is improved. be able to.
[0091]
Furthermore, in addition to the hollow anode discharge at the plasma outlet 7, the hollow cathode discharge is generated, so that the electron temperature of the plasma between the electrodes 10 and 6 is lowered and the electron density is increased. Will improve. Furthermore, since the high-frequency voltage at the cathode electrode 10 decreases and the self-bias voltage increases due to the hollow cathode discharge, the space potential of the plasma generated between the electrodes 10 and 6 also increases. As a result, a hollow anode discharge is likely to occur at the plasma outlet 7, and a synergistic effect can be obtained that high-density plasma can be generated at the plasma outlet 7. Further, for the same reason, electric field concentration is likely to occur in the plasma generation region 3, and non-uniform discharge that is locally converted to high-density plasma can be generated.
[0092]
FIG. 3 is a schematic view of a surface treatment apparatus 21 according to a third embodiment of the present invention. The apparatus 21 is different from the first embodiment described above in that the magnet 11 is arranged on the inner wall surface of the recess 10a formed on the cathode electrode 10 and the inner wall surface of the plasma outlet 7; This is the same as the surface treatment apparatus 1 of the first embodiment. The magnet 11 only needs to be arranged so as to apply a magnetic field to the recess 10a and the plasma outlet 7. Accordingly, the magnet 11 is embedded in the inner wall surface as shown in FIG. 3, for example, embedded in the cathode electrode 10 above the recess 10 a, or outside the cathode electrode 10. It is also possible to arrange them, or a combination of these arrangements. In arranging these magnets 11, it is preferable to attach the magnets 11 so that the magnets 11 are not directly exposed to plasma.
[0093]
It is preferable that the magnetic field of the magnet 11 is applied so that the direction of the lines of magnetic force is parallel to the axial directions of the recess 10 a and the plasma outlet 7. The strength of the magnet is 1 to 2000 mT at the axial center of the recess 110 a and the plasma outlet 7, and 2 to 2000 mT at the inner wall surface and the vicinity thereof, more preferably 5 to 500 mT at the axial center and at the inner wall surface and the vicinity thereof. 5 to 1000 mT.
[0094]
In this way, by forming a magnetic field in the recess 10a and the plasma outlet 7, the trajectory of electrons generated in the plasma is adjusted by the magnetic field, and electrons are introduced into the recess 10a and the plasma outlet 7. Can stay longer. By adjusting the electron trajectory, the action time of the electrons on the source gas can be extended without increasing the electron energy (electron temperature), so that the generation of active species is promoted and the film formation rate is improved.
[0095]
Further, when the magnet 11 is arranged to form a magnetic field, the allowable range of the dimension of the opening width W or depth D of the recess 10 a or the opening width W of the plasma outlet 7 is not provided with the magnet 11. Compared to about 30%.
[0096]
In this embodiment, the magnets 11 are arranged in all the recesses 10a and the plasma outlets 7. However, the magnets 11 are arranged only in selected ones instead of the magnets 11 in all of them. You can also. Furthermore, it is possible to form a magnetic field by means such as an electromagnet. Further, the arrangement of the magnetic field including the polarity of the magnet and the intensity of the magnetic field are arbitrarily set so as to increase the plasma density.
[0097]
  FIG. 4 is a schematic view of a surface treatment apparatus 22 according to a fourth embodiment of the present invention. This surface treatment device 22 is also provided between two regions of the plasma generation region 3 and the substrate treatment region 4 in the casing 2.Anode electrode6 'is interposed. SaidAnode electrodeReference numeral 6 'denotes an anode electrode of a plasma generating electrode, and a circular plasma outlet 7' is formed at the center of the anode electrode 6 '.
[0098]
The cathode electrode 10 is formed with a plurality of concave portions 10a having a circular cross section on the surface facing the anode electrode 6 '. The opening width W of the concave portion 10a is W ≦ 5L (e) or W ≦ 20X. Is set in a range that satisfies either of the above. More preferably, the opening width W is set in a range of X / 5 ≦ W. By setting the diameter of the recess 10a within such a range, hollow cathode discharge occurs in the recess 10a.
[0099]
The above configuration of the present embodiment is the same as that of the second embodiment described above. However, the opening width W of the plasma outlet 7 ′ formed in the anode electrode 6 ′ is large, or the length (thickness) T Therefore, it is different from the surface treatment apparatus 1 of the first embodiment described above in that no hollow discharge is generated at the plasma outlet 7 ′.
[0100]
In this embodiment, since hollow discharge does not occur at the plasma outlet 7 ', the surface treatment speed and quality are slightly inferior to those of the first embodiment described above, but hollow cathode discharge occurs in the recess 10a of the cathode electrode 10. Therefore, the processing speed and processing quality are improved as compared with the conventional surface processing apparatus.
[0101]
FIG. 5 is a schematic view of a surface treatment apparatus 23 according to a fifth embodiment of the present invention. The apparatus 23 differs from the second embodiment described above in that the cathode electrode 12 which is the hollow plasma generating electrode of the present invention is a hollow cylindrical hollow body, but the other configuration is the surface treatment of the second embodiment. Same as device 1.
[0102]
  The cathode electrode 12, which is a hollow body,Anode electrode 6A plurality of through-holes 12b having a circular cross section communicating with the inside of the cavity are formed in a portion opposed to the cathode electrode 12, that is, the lower wall portion 12a of the cathode electrode 12. The through holes 12b are preferably formed in an arrangement as shown in FIGS. The through hole 12b is more preferably formed at a position avoiding the position directly above the plasma outlet 7 formed in the anode electrode 6, that is, at the arrangement shown in FIG.
[0103]
The opening width W, that is, the diameter W is set to a range satisfying either W ≦ 5L (e) or W ≦ 20X so that the through hole 12b can be a hollow cathode discharge generation region. However, L (e) is the atom or molecular species having the smallest diameter among the source gas species and the electrically neutral atoms and molecular species (active species) generated by decomposition under the desired plasma generation conditions. X is the thickness of the sheath layer generated under the desired plasma generation conditions. The opening width W is preferably set in a range of X / 20 ≦ W, and more preferably in a range of X / 5 ≦ W.
[0104]
Further, the plurality of through holes 12b may not have the same opening width W, and different opening widths W may be appropriately set in order to uniformly generate hollow cathode discharge in the plurality of through holes 12b. it can. In particular, the through hole 12b near the center decreases the opening width W and gradually increases the opening width W in the outer edge direction according to the frequency of the applied power or according to other conditions, or increases the opening width W near the center. It is preferable that the opening width W be gradually increased in the outer edge direction.
[0105]
When the gas pressure is in the range of 10 to 1400 Pa among the plasma generation conditions, the diameter of the through hole 12b is set in the range of 0.1 to 100 mm, more preferably 1 to 20 mm. By setting the diameter of the through hole 12b within this range, a hollow cathode discharge is generated in the through hole 12b.
[0106]
Further, the length T of the through hole 12b, that is, in the case of the present embodiment, the thickness T of the lower wall portion 12a generally has a lower limit of X / 50. The upper limit is determined by device size constraints. In the case of the gas pressure and diameter described above, the length T of the through hole 12b is preferably 0.3 to 70 mm.
[0107]
In the present embodiment, the through hole 12b has a circular cross section, but may have any other shape such as an ellipse, a rectangle, a polygon, and an indefinite shape. The cross-sectional area may not be constant, and the cross-sectional area may be changed in the axial direction. Furthermore, the through-hole 12b may have a slit structure having a rectangular cross section, or a slit structure having a one-dimensional extension such as a spiral shape or a meandering shape as shown in FIG. In the case of such a slit structure, the opening width W of the through-hole 12b is the slit width, and this slit width is set within the above range. The slit width does not have to be constant, and can be gradually increased or decreased from the center toward the outer edge. Moreover, you may form a partial unevenness | corrugation in the inner wall face of the said through-hole 12b. The plurality of through holes 12b do not have to have the same size and the same form, and a plurality of through holes 12b having different sizes and forms may be formed.
[0108]
Furthermore, in this embodiment, the facing distance inside the cavity along the direction in which the through hole 12b of the cathode electrode 12 is formed, that is, the inside of the cavity of the cathode electrode 12 can be used as a generation region of a hollow cathode discharge, that is, In the drawing, the vertical height H is set in a range satisfying either H ≦ 5L (e) or H ≦ 20X. However, L (e) is the atom or molecular species having the smallest diameter among the source gas species and the electrically neutral atoms and molecular species (active species) generated by decomposition under the desired plasma generation conditions. X is the thickness of the sheath layer generated under the desired plasma generation conditions. The height H inside the cavity is preferably set in the range of X / 20 ≦ H, and more preferably in the range of X / 5 ≦ H. When the gas pressure is within the range of 10 to 1400 Pa as described above and the dimension of the through hole 11b is within the above range, the height H inside the cavity is 0.1 to 100 mm. Preferably, the height H inside the cavity is more preferably set to 1 to 20 mm.
[0109]
In the illustrated example, the height H inside the cavity is constant. However, the height H may not be constant, and the height H is set within the above-described range in at least a part of the inside of the cavity. do it. In order to generate a hollow cathode discharge uniformly over almost the entire area inside the cavity, the height H inside the cavity near the center is reduced according to the frequency of the applied power or according to other conditions, and the height in the outer edge direction is increased. It is preferable to gradually increase the height H, or to increase the height H near the center and gradually decrease the height H in the outer edge direction.
[0110]
Further, in the illustrated example, the cathode electrode 12 is a hollow body having a substantially uniform wall portion and hollow as a whole. However, the peripheral wall portion is thickened so that only the central portion is hollow or the local portion is hollow. A typical hollow part can also be formed. Moreover, a recessed part can also be formed in the hollow part.
[0111]
A cylindrical gas supply port 12d is formed in the center of the upper wall portion 12c of the cathode electrode 12, and a source gas such as monosilane and plasma are promoted from the gas supply port 12d into the cavity of the cathode electrode 11. In addition, a mixed gas with a carrier gas for stabilizing the plasma and conveying the source gas to the substrate S is introduced. The gas supply port 12d is not limited to a cylindrical shape, and may be a rectangular cylindrical shape. Further, the formation position of the gas supply port 12d is not limited to the center of the upper wall portion 12c, and any number can be formed at any position.
[0112]
The mixed gas introduced into the cathode electrode 12 from the gas supply port 12d is introduced into the plasma generation region 3 from the through hole 12b in a shower shape. As described above, the mixed gas is once stored in the cathode electrode 12 and then introduced into the plasma generation region 3 in the form of a shower from the through-hole 12b, so that the mixed gas has a uniform concentration and pressure. It can be introduced into the plasma generation region 3.
[0113]
It should be noted that only the carrier gas is introduced into the cavity of the cathode electrode 12 and a different inlet is provided for the source gas separately to provide the inside of the plasma generation region 3, the inside of the film forming region 4, or the plasma outlet. 7 can also be introduced.
[0114]
When high frequency power is applied to the cathode electrode 12 by a high frequency power source P, a discharge occurs between the electrodes 12 and 6, and plasma is generated in the plasma generation region 3. A transition from normal glow discharge to discharge including hollow cathode discharge is made according to the applied high frequency power. At this time, the cathode electrode 12 generates a hollow cathode discharge in the through hole 12b, generates a new plasma in the through hole 12b, and also generates a hollow cathode discharge in the cavity of the cathode electrode 12. New plasma is generated. Therefore, the plasma generated in the plasma generation region 3 becomes a high-density plasma, and the number of active species contributing to the film forming process increases, so that the surface treatment speed is increased.
[0115]
Further, since the cathode electrode 12 is a hollow body and a through hole 12b is formed to generate plasma in the through hole 12b and the inside of the cavity, the surface area of the cathode electrode 12 that is substantially in contact with the plasma is It further increases compared to the case of the second embodiment described above. As a result, the self-bias at the time of discharge generation can be brought to the positive side, the excitation and decomposition reaction of the source gas in the vicinity of the grounded anode electrode 6 is promoted, and the surface treatment speed is further improved. Can be made.
[0116]
Furthermore, a magnet can be arranged at an appropriate location so as to form a magnetic field inside the cavity of the cathode electrode 12 which is a hollow body or in the through hole 12b. In this case, the magnetic field of the magnet is preferably applied so that the direction of the magnetic lines of force is parallel to the axial direction of the through-hole 12b and so as to be parallel to the electrode surface inside the cavity. The strength of the magnet is 1 to 2000 mT at the center of the through hole and inside the cavity, and 2 to 2000 mT at and around the inner wall surface inside the through hole and the cavity, more preferably 5 to 500 mT at the center and around the inner wall surface and the vicinity thereof. 5 to 1000 mT.
[0117]
In this way, by forming a magnetic field inside the through-hole 12b and the cavity, the trajectory of electrons generated in the plasma is adjusted by the magnetic field, and the electrons stay in the through-hole 12b and the cavity for a long time. Can do. By adjusting the electron trajectory, the action time of the electrons on the source gas can be extended without increasing the electron energy (electron temperature), so that the generation of active species is promoted and the film formation rate is improved.
[0118]
It is not necessary to form the magnetic field in all the through holes 12b, and the magnetic field can be formed only in one selected. It is also possible to form a magnetic field by means such as an electromagnet.
[0119]
Furthermore, in order to increase the plasma density generated by the hollow cathode discharge in the through hole 12b or the cavity in the cathode electrode 12, from the viewpoint of efficiently generating the hollow cathode discharge in the through hole 12b, A larger length T is advantageous, and a stronger plasma can be generated. However, it is desirable that the thickness of the lower wall portion 12a of the cathode electrode 12 be a minimum thickness that can withstand the gas pressure and applied power introduced into the cavity from the viewpoint of material cost.
[0120]
Therefore, in order to increase the length T of the through hole 12b, it is desirable to attach a nozzle body to the periphery of the through hole 12b. The nozzle body may protrude from the through hole 12b toward the plasma generation region 3 or may protrude into the cavity. Furthermore, you may project on both sides. In addition, the nozzle body can be constituted by a magnet. However, it is preferable that the magnet is not directly exposed to the plasma.
[0121]
The nozzle body may be arranged with its center line aligned with the line of the through hole 12b, and the center line of the nozzle body is arranged at an angle with respect to the axis of the through hole 12b. It can also be arranged diagonally. Further, the nozzle body can be arranged in a spiral shape with a cylindrical body having a constant cross-sectional area, a cylindrical body having a shape that gradually increases or decreases the cross-sectional area, and a tubular nozzle body. Such deformation of the nozzle body can also be applied to the nozzle body attached to the plasma outlet 7 or the recess 10a described above.
[0122]
Furthermore, in order to increase the surface area of the cathode electrode 12 in contact with the plasma, the inside of the cavity of the cathode electrode 12 can be partitioned by a partition wall extending in the height direction. Since the surface area can be freely adjusted in this way, the self-bias of the cathode electrode 12 can be freely controlled. The partition does not have to be in close contact with the upper and lower wall portions of the cathode electrode 12, and a space formed by a gap may be communicated with each other.
[0123]
It is desirable to provide a gas supply port in each partitioned space. Alternatively, a gas supply port can be formed at a position opening in the peripheral wall portion of the anode electrode, or a plurality of gas supply ports can be formed in combination. Only the carrier gas is introduced from the gas supply port of the cathode electrode 12, and the source gas is provided with a gas supply port of the anode electrode, or a different introduction port, so that the inside of the plasma generation region 3 and the film formation process are performed. It can also be introduced into the region 4 or in the middle of the plasma outlet 7.
[0124]
In the fifth embodiment described above in which the cathode electrode 12 is a hollow body, a hollow cathode discharge is generated in almost the entire area inside the cavity of the cathode electrode 12 as shown in FIG. However, depending on the height inside the cavity of the cathode electrode 12, the shape, number, and arrangement of the through holes 12d, and the arrangement of magnets, hollow discharge may not occur over the entire area inside the cavity. A hollow cathode discharge may occur only in a part of the inside of the cavity, or a hollow cathode discharge may occur nonuniformly inside the cavity. As a general tendency, a hollow discharge that is brighter than the others is generated in the hollow portion in the vicinity of the through hole in which the hollow discharge is generated. In any of the through holes 12b, no hollow discharge is generated, and even if the hollow discharge is generated only in at least part of the inside of the cavity, there is an effect of improving both the processing speed and the quality.
[0125]
FIG. 6 is a schematic view of a surface treatment apparatus 24 according to the sixth embodiment. The device 24 differs from the fifth embodiment described above in that the inner wall surface in the cavity is made of an insulator so that hollow cathode discharge does not occur in the cavity of the cathode electrode 12 '. The configuration is the same as that of the surface treatment apparatus 23 of the fifth embodiment.
[0126]
However, a part of the electrode may be exposed on the inner surface of the lower wall portion 12a of the cathode electrode 12 '. In this case, the plasma generated in the plasma generation region 3 enters the cavity through the through hole 12b. The exposed electrode surface can be scratched. Thereby, the surface area of the cathode electrode 12 ′ with which the plasma can substantially contact can be increased, and the self-bias can be increased.
[0127]
Further, in order to prevent the hollow cathode discharge from being generated inside the cavity of the cathode electrode 12 ', in addition to the construction of the inner wall surface as described above, the method of increasing the height H inside the cavity However, since this height H also changes depending on the RF power and gas pressure, a method of configuring the inner wall surface with an insulator is more reliable.
[0128]
In this way, the plasma generation location can be controlled, the surface area of the cathode electrode 12 ′ in contact with the plasma can be adjusted, and the self-bias can also be controlled, so that the plasma having a strength corresponding to the application can be generated.
[0129]
As a modification of the cathode electrode 12 that is the above-described hollow body, for example, a lower wall portion having a plurality of through holes 15b that communicate with the inside of the cavity, such as the cathode electrode 15 that is the hollow body shown in FIG. The space between 15a and the upper wall portion 15c can be divided into a plurality of stages in the vertical direction by one or more partition walls 15e having one or more through holes 15d. At this time, a plurality of through-holes 13b formed in the lower wall portion 15a and a plurality of through-holes formed in the partition wall 15e as in the cathode electrode 15 'which is a hollow body shown in FIG. 7B. It is preferable to form the respective through holes 15b and 15d so that 15d does not overlap with each other in the vertical direction.
[0130]
Further, the number of the through holes 15b and 15d may be different between the lower wall portion 15a and the partition wall 15e. Moreover, the opening dimension of each through-hole 15b, 15d may also differ in the lower wall part 15a and the partition wall 15e, Furthermore, several penetration hole 15b of the lower wall part 15a and several penetration of the partition wall 15e are sufficient. Also in the holes 15d, it is not necessary to make all the openings uniformly uniform, and the openings can be changed so as to gradually decrease or gradually increase from the central portion toward the outer edge.
[0131]
As still another modified example of the cathode electrode 12 which is the above-described hollow body, a plurality of hollow electrode members 16a are vertically arranged in a plurality of stages by connecting ports 16b as in the cathode electrode 16 having a hollow body shown in FIG. It can also be connected to. It should be noted that any point in the space shown can be a hollow discharge plasma generation region.
[0132]
In any of the above-described embodiments, the plasma generation region 3 is provided above the surface treatment apparatus and the substrate treatment region 4 is provided below the surface treatment apparatus. On the contrary, the plasma generation region is disposed below. It is also possible to provide a type of apparatus in which a substrate processing region is provided above and a plasma flows out from below to above. Furthermore, it is also possible to provide a type of apparatus in which the plasma generation region and the substrate processing region are horizontally arranged in the left and right within the casing of the surface processing apparatus, and the plasma flows out in the lateral direction. In either case, the substrate can be disposed so as to face the plasma outlet and orthogonal to the plasma outflow direction, or the substrate can be disposed in parallel with the plasma outflow direction. The plasma generating means is not limited to a pair of plasma generating electrodes. For example, discharge having three or more electrodes, microwave discharge, capacitively coupled discharge, inductively coupled discharge, PIG discharge, electron beam excited discharge. It is also possible to adopt a plasma generating means or the like.
[0133]
As shown in FIGS. 8 (a) and 8 (b), another electrode 13 may be disposed in the vicinity of the anode electrode side and / or the opposite side of the cathode electrodes 10 and 12 where hollow cathode discharge occurs. it can. The other electrode 13 has a large number of small holes 13a having an opening width smaller than the opening width W of the through hole 12b formed in the recess 10a formed in the cathode electrode 10 or the cathode electrode 12 which is a hollow body. Alternatively, the other electrode 13 may have a mesh shape. Even in the case of a cathode electrode having a through hole in which a hollow cathode discharge is generated, similarly, another electrode in which many small holes smaller than the opening width W of the through hole can be arranged. .
[0134]
The other electrode 13 is biased to an arbitrary voltage including a floating state, and is particularly preferably set to a voltage value between the voltage of the grounded anode electrode 6 and the maximum value of the space potential of the plasma, Alternatively, it is set to a voltage value between the voltage of the cathode electrode 10 where the hollow cathode discharge is generated and the maximum value of the space potential of the plasma.
[0135]
Further, if the small hole 13a formed in the other electrode 13 is formed at a position corresponding to the concave portion 10a or the through hole 12b of the cathode electrodes 10 and 12, as shown in FIG. It becomes possible to perform ultra-high density hollow cathode discharge, which is a higher current discharge, confined in the region.
[0136]
Alternatively, as shown in FIGS. 9 (a) and 9 (b), in the recess 10a ″ formed in the cathode electrode 10 ″ and the through hole 12b ″ formed in the cathode electrode 12 ″, the area of the opening portion is the above-mentioned. By forming it sufficiently smaller than the cross-sectional area of the recess 10a "and other portions of the through-hole 12b", electrons can be efficiently put into the recess 10a "and the through-hole 12b" which are hollow cathode discharge regions or in the hollow portion. Can be confined. In the figure, the concave portion 10a ″ and the through hole 12b ″ have a cylindrical shape in the upper half and a hemispherical shape in the lower half, but they may have a conical shape, a pyramid shape, or a spindle shape.
[0137]
FIG. 10 is a schematic view of a surface treatment apparatus 25 according to the seventh embodiment of the present invention. The apparatus 25 is different from the first embodiment described above in that the plate member 14 functioning as an anode electrode arranged in parallel to face the cathode electrode 5 is a hollow body, but other configurations are the same as those in the first embodiment. This is substantially the same as the surface treatment apparatus 1 of the example.
[0138]
In the center of the anode electrode 14, a single plasma outlet 7 is formed that penetrates the upper wall portion 14 a and the lower wall portion 14 b in a straight line. Further, in the present embodiment, the facing distance along the direction of formation of the plasma outlet 7 inside the cavity, that is, the upper and lower sides in the figure, so that the inside of the cavity of the anode electrode 14 can be a generation region of a hollow anode discharge. The height H between the wall portions 14a and 14b is set in a range satisfying either H ≦ 5L (e) or H ≦ 20X. However, L (e) is the atom or molecular species having the smallest diameter among the source gas species and the electrically neutral atoms and molecular species (active species) generated by decomposition under the desired plasma generation conditions. X is the thickness of the sheath layer generated under the desired plasma generation conditions. The height H inside the cavity is preferably set in the range of X / 20 ≦ H, and more preferably in the range of X / 5 ≦ H.
[0139]
In this embodiment, in addition to the hollow anode discharge at the plasma outlet 7, a hollow anode discharge is generated inside the cavity of the anode electrode 14, and a new plasma is also generated inside the cavity of the anode electrode 14. . Therefore, the density of the process plasma that reaches the substrate S is further increased and the number of active species that contribute to the film forming process is increased, so that the surface treatment speed is improved and the treatment quality is further improved. Of course, even in the case where hollow discharge is generated only in either one, both the processing speed and quality are improved as compared with the conventional case.
[0140]
In the illustrated example, the height H inside the cavity of the anode electrode 14 is constant, but the height H may not be constant. In order to generate a hollow anode discharge uniformly over almost the entire area inside the cavity, the height H inside the cavity near the center is reduced according to the frequency of the applied power or according to other conditions, and the height in the outer edge direction is increased. It is preferable to gradually increase the height H, or to increase the height H near the center and gradually decrease the height H in the outer edge direction.
[0141]
Alternatively, it is not necessary for the anode electrode 14 to generate a hollow anode discharge in the entire inside of the cavity, and if the hollow anode discharge can be generated in at least a part, the quality of the surface treatment and the processing speed can be improved.
[0142]
FIG. 11 shows a modification of the anode electrode 14 that is the above-described hollow body. The anode electrode 14 described above is formed so as to penetrate the single plasma outlet 7 at the center. However, as in the anode electrode 14 'shown in FIG. 11, the upper wall portion 14a and the lower wall portion 14b are respectively hollow. It is also possible to form a plurality of through holes 14c as plasma outlets communicating with the inside. In this case, it is preferable that the through hole 14c of the upper wall portion 14a and the through hole 14c of the lower wall portion 14b are formed so as to be shifted from each other so as not to be aligned vertically. Furthermore, it is preferable to form the through holes 14c in the arrangement shown in FIGS.
[0143]
Further, the plurality of through holes 14c may not have the same opening width W, and different opening widths W may be appropriately set in order to uniformly generate hollow anode discharge in the plurality of through holes 14c. it can. In particular, the through hole 14c near the center decreases the opening width W and gradually increases the opening width W in the outer edge direction according to the frequency of the applied power or according to other conditions, or the opening width W near the center. It is preferable that the opening width W be gradually increased in the outer edge direction.
[0144]
Further, the length T of the through hole 14c, that is, in the case of the present embodiment, the thickness T of the lower wall portion 14a has a lower limit of about X / 50. The upper limit is determined by device size constraints. In the case of the above-described gas pressure and diameter, the length T of the through hole 14c is preferably 0.1 to 70 mm.
[0145]
In the present embodiment, the through hole 14c has a circular cross section, but may have any other shape such as an ellipse, a rectangle, a polygon, and an indefinite shape. The cross-sectional area may not be constant, and the cross-sectional area may be changed in the axial direction. Furthermore, the through hole 14c may have a slit structure with a rectangular cross section, or a slit structure having a one-dimensional extension such as a spiral shape or a meandering shape as shown in FIG. In the case of such a slit structure, the opening width W of the through hole 14c is the slit width, and this slit width is set within the above-described range. Moreover, you may form a partial unevenness | corrugation in the inner wall face of the said through-hole 14c. The plurality of through holes 14c do not have to have the same size and the same form, and a plurality of through holes 14c having different sizes and forms may be formed.
[0146]
The anode electrode 14 'may be formed with a gas supply port 8' that opens to the inner wall surface of the through hole 14c or the cavity. For example, in the case of a film forming process, only the carrier gas is introduced into the plasma generation region 3, and the source gas such as monosilane is introduced from the gas supply port 8 'of the anode electrode 14'. It is possible to prevent decomposition in an unnecessary space and to efficiently contribute the source gas to the film forming process. The gas supply ports 8 'can be provided in all of the plurality of through holes 14c, or the gas supply ports 8' can be provided only in some of the through holes 14c. Furthermore, a plurality of gas supply ports 8 'can be opened on the inner wall surface inside the cavity.
[0147]
Further, FIG. 12 and FIG. 13 show a modification in which the plasma density generated by hollow anode discharge in the cavity of the anode electrode 14 ′ and in the through hole 14c is increased.
First, from the viewpoint of efficiently generating a hollow anode discharge in the through hole 14c, it is advantageous that the length T of the through hole 14c is large, and a stronger plasma can be generated. However, it is desirable that the upper and lower wall portions 14a and 14b of the anode electrode have a minimum thickness that can withstand the gas pressure and applied power introduced into the cavity from the viewpoint of material cost.
[0148]
Therefore, in order to increase the length T of the through hole 14c, it is desirable to attach the nozzle body 17 to the periphery of the through hole 14c of the lower wall portion 14b. The nozzle body 17 may project from the through-hole 14c toward the substrate processing region 4 or project into the cavity body 14a. Furthermore, you may project on both sides. Moreover, the nozzle body 17 can also be comprised with the magnet 11, as shown in FIG. At this time, the magnet 11 is preferably arranged so as not to be directly exposed to the plasma.
[0149]
In addition, although all the nozzle bodies 17 shown in FIG. 12 are arranged with their center lines aligned with the lines of the through holes 14c, the center lines of the nozzle bodies 17 are angled with respect to the axes of the through holes 14c. In other words, the nozzle body 17 can be arranged obliquely. The nozzle body 17 shown in FIG. 12 is a cylindrical body having a constant cross-sectional area, but is not limited to such a shape, and may be a cylindrical body having a shape that gradually increases or decreases its cross-sectional area. Furthermore, a tubular nozzle body can be arranged in a spiral shape.
[0150]
Further, in order to increase the surface area of the anode electrode 14 'with which the plasma contacts, a partition wall extending in the vertical direction or a partition wall extending in the horizontal direction is provided inside the cavity of the anode electrode 14', and the interior is divided into a plurality of chambers. You can also. In addition, all the through-holes 14c formed in each chamber divided | segmented inside may be the same, or can also differ. The partition extending in the vertical direction may be formed with a gap between the upper and lower wall portions 14a and 14b, and the chambers may communicate with each other.
[0151]
Further, as shown in FIG. 13, the anode electrode 14 'has a magnet 11 which is connected to the inner peripheral surface of each through-hole 14c and the upper and lower surfaces so as to apply a magnetic field to the through-hole 14c serving as a plasma outlet and the inside of the cavity. It can be embedded in the wall portions 14a and 14b or the peripheral wall portion, or can be arranged in the vicinity thereof. The magnet 11 is applied with a magnetic field such that the direction of the lines of magnetic force thereof is parallel to the axial direction of the through hole 14c, or is applied so that the direction of the lines of magnetic force is parallel to the upper and lower wall portions 14a, 14b. It is preferable that it is arranged.
[0152]
In this way, by forming a magnetic field inside the through-hole 14c and the cavity, the trajectory of electrons generated in the plasma is adjusted by the magnetic field, so that the electrons stay in the through-hole 14c and the cavity for a long time. Can do. By adjusting the electron trajectory, the action time of the electrons on the source gas can be extended without increasing the electron energy (electron temperature), so that the generation of active species is promoted and the film formation rate is improved. The structure shown in FIGS. 12 and 13 can be applied to the cathode electrodes 10, 10 ′, 10 ″, 12, 12 ′, 12 ″, 15, 15 ′, 16 shown in FIGS. Is obtained.
[0153]
In the surface treatment apparatus 25 of the seventh embodiment in which the plate member 14 serving as the anode electrode is a hollow body, the cathode electrode 5 has a hollow cathode discharge region as shown in the second to sixth embodiments described above. Of course, it is also possible to change to the cathode electrodes 10 and 12 which have. In that case, the effects of the above-described embodiments are also obtained, and the density of the process plasma is increased by the hollow anode discharge or the hollow cathode discharge, and various processing speeds are remarkably improved.
[0154]
FIG. 14 is a schematic view of a surface treatment apparatus 26 according to the eighth embodiment of the present invention. The surface treatment apparatus 40 is formed of a hollow body, and the inside of the plate member 18 that is also an anode electrode constitutes a substrate processing region 4 ′.
The anode 18 made of a hollow body has a through hole 18b formed at the center of the upper wall portion 18a, and this through hole 18b constitutes a plasma outlet. The central portion of the inner surface of the lower wall portion 18c of the anode electrode 18 constitutes a substrate support, and a plurality of exhaust ports 18d are formed in the peripheral portion of the lower wall portion 18c. Further, a heating means for the substrate can be provided in the central portion of the lower wall portion 18c. The substrate support position in the anode electrode 18 and the exhaust port 18d formation position are not limited to those described above, and any position can be selected.
[0155]
In the present embodiment, the opening width W of the through hole 18b is set to either W ≦ 5L (e) or W ≦ 20X so that the through hole 18b of the anode electrode 18 can be a hollow anode discharge generation region. Is set to satisfy the range. Further, the opening width W is preferably set in a range of X / 20 ≦ W, and more preferably set in a range of X / 5 ≦ W. Further, in this embodiment, the height H inside the cavity is set to either H ≦ 5L (e) or H ≦ 20X so that the inside of the cavity of the anode electrode 18 can be a hollow anode discharge generation region. It is set in a range that satisfies the above. The height H inside the cavity is also preferably set in the range of X / 20 ≦ H, and more preferably in the range of X / 5 ≦ H.
[0156]
However, L (e) is the atom or molecular species having the smallest diameter among the source gas species and the electrically neutral atoms and molecular species (active species) generated by decomposition under the desired plasma generation conditions. X is the thickness of the sheath layer generated under the desired plasma generation conditions.
[0157]
In the substrate processing apparatus 26, the substrate processing region 4 ′ is formed inside the cavity of the anode electrode 18, and a hollow anode discharge is generated inside the cavity of the anode electrode 18. The density of the resin is extremely increased, and the processing speed is remarkably improved. However, the substrate processing apparatus 26 is not suitable for the film forming process because the ion damage to the substrate S due to plasma is large, and the apparatus 26 is more suitable for the etching, ashing, or ion doping process.
[0158]
15 and 16 show modifications of the plate member (anode electrode) made of a hollow body that constitutes the substrate processing region 4 '. An anode electrode 18 'shown in FIG. 15 differs from the above-described anode electrode 18 in that a plurality of through holes 18b constituting a plasma outlet are formed in the upper wall portion 18a. The through holes 18b are preferably formed in an arrangement as shown in FIGS.
[0159]
The plurality of through holes 18b have a circular cross section in the present embodiment, but may have any other shape such as an ellipse, a rectangle, a polygon, and an indefinite shape. The cross-sectional area may not be constant, and the cross-sectional area may be changed in the axial direction. Furthermore, the through-hole 18b may have a slit structure having a rectangular cross section, or a slit structure having a one-dimensional extension such as a spiral shape or a meandering shape as shown in FIG. In the case of such a slit structure, the opening width W of the through hole 18b is the slit width, and this slit width is set within the above-described range. Moreover, you may form a partial unevenness | corrugation in the inner wall face of the said through-hole 18b. The plurality of through holes 18b do not have to have the same size and the same form, and a plurality of through holes 18d having different sizes and forms may be formed.
[0160]
In addition, the anode electrode 18 ″ shown in FIG. 16 has the through holes 18b and exhaust ports 18d, which are plasma outlets, and the magnet 11 so as to apply a magnetic field to the inside of the cavity, and the inner peripheral surfaces of the through holes 18b and exhaust ports 18d. The magnet 11 can be embedded in the upper and lower wall portions 18a, 18c, or the peripheral wall portion, or can be arranged in the vicinity thereof.The magnet 11 has a direction of magnetic lines in the axial direction of the through hole 18b and the exhaust port 18d. It is preferable that the magnetic field is applied so that the magnetic field is applied in parallel with the upper and lower wall portions 18a and 18d. FIG. 16 shows various specific examples of the arrangement of the magnets, and the arrangement of the magnets may be only a part.
[0161]
In this way, by forming a magnetic field inside the through-hole 18b or the cavity which is a plasma outlet, the trajectory of electrons generated in the plasma is adjusted by the magnetic field, and an electron is inside the through-hole 18b or the cavity. Can stay longer. By adjusting the electron trajectory, the action time of the electrons on the source gas can be extended without increasing the electron energy (electron temperature), so that the generation of active species is promoted and the film formation rate is improved. Also in the electrode 18, the above-described configuration such as a partition plate and a nozzle body shown in FIG.
[0162]
In the various embodiments and modifications of the present invention described above, high-frequency power is supplied to the plasma generating electrode by the high-frequency power source P, but a DC voltage can also be applied by a DC power source. Alternatively, the bias may be applied by a DC or AC power source or a pulse power source, respectively.
Further, a mesh-like electrode may be installed between the substrate S disposed in the surface treatment region 4 and the plasma outlet 7 to configure a triode type, and various biases may be applied. Further, a bias may be applied only to the nozzle body or the through-hole portion by a direct current, an alternating current, or a pulse power source. In this case, only the nozzle body or the through hole is electrically insulated from the other parts of the electrode.
[Brief description of the drawings]
FIG. 1 is a schematic view of a surface treatment apparatus according to a first embodiment of the present invention.
FIG. 2 is a schematic view of a surface treatment apparatus according to a second embodiment of the present invention.
FIG. 3 is a schematic view of a surface treatment apparatus according to a third embodiment of the present invention.
FIG. 4 is a schematic view of a surface treatment apparatus according to a fourth embodiment of the present invention.
FIG. 5 is a schematic view of a surface treatment apparatus according to a fifth embodiment of the present invention.
FIG. 6 is a schematic view of a surface treatment apparatus according to a sixth embodiment of the present invention.
FIG. 7 is a schematic view showing another embodiment of a hollow cathode electrode.
FIG. 8 is a schematic view of a cathode electrode portion in a surface treatment apparatus according to another embodiment of the present invention.
FIG. 9 is a schematic view of a cathode electrode portion in a surface treatment apparatus according to still another embodiment of the present invention.
FIG. 10 is a schematic view of a surface treatment apparatus according to a seventh embodiment of the present invention.
FIG. 11 is a schematic view showing a modification of the anode electrode in the seventh embodiment.
FIG. 12 is a schematic view showing another modification of the anode electrode in the seventh embodiment.
FIG. 13 is a schematic view showing still another modified example of the anode electrode in the seventh embodiment.
FIG. 14 is a schematic view of a surface treatment apparatus according to an eighth embodiment of the present invention.
FIG. 15 is a schematic view showing a modification of the anode electrode in the eighth embodiment.
FIG. 16 is a schematic view showing another modification of the anode electrode in the eighth embodiment.
FIG. 17 is a view showing an arrangement example of a large number of through holes or recesses.
FIG. 18 is a view showing another arrangement example of a large number of through holes or recesses.
FIG. 19 is a diagram showing still another example of arrangement of a large number of through holes or recesses.
FIG. 20 is a diagram showing still another arrangement example of a large number of through holes or recesses.
FIG. 21 is an explanatory diagram of a spiral through hole or recess.
[Explanation of symbols]
1,20-26 Surface treatment equipment
2 Casing
2a Upper wall
3 Plasma generation region
4 Substrate processing area
5 Cathode electrode
6 Plate member (Anode electrode)
7 Plasma outlet
8 Gas supply port
9 Substrate support
10 Cathode electrode
10a recess
11 Magnet
12 Cathode electrode
12a Lower wall
12b Through hole
12c Upper wall
12d gas supply port
13 Other electrodes
13a small hole
14 Anode electrode
14a Upper wall part
14b Lower wall
14c Through hole
15 Cathode electrode
15a Lower wall
15b Through hole
15c upper wall
15d through hole
15e partition wall
16 Cathode electrode
16a Hollow electrode member
16b Connection port
17 Nozzle body
18 Anode electrode
18a Upper wall
18b Through hole
18c lower wall
18d exhaust port
S substrate
P High frequency power supply

Claims (11)

Plasma is generated by the plasma generating means in a casing having a plasma generating means, a raw material gas inlet, and a substrate support table to turn the source gas into plasma, and the surface of the substrate placed on the substrate support table is converted into plasma. A surface treatment apparatus for treating,
An anode electrode having one or more plasma outlets is interposed between the plasma generation region having the plasma generation means and the substrate processing region having the substrate support so as to be spaced apart from the inner wall surface of the casing. And
At least one said anode electrode has one or more hollow discharge generation | occurence | production areas, The surface treatment apparatus characterized by the above-mentioned. Plasma is generated by the plasma generating means in a casing having a plasma generating means, a raw material gas inlet, and a substrate support table to turn the source gas into plasma, and the surface of the substrate placed on the substrate support table is converted into plasma. A surface treatment apparatus for treating,
An anode electrode having one or more plasma outlets is interposed between the plasma generation region having the plasma generation means and the substrate processing region having the substrate support so as to be spaced apart from the inner wall surface of the casing. And
The surface treatment apparatus according to claim 1, wherein a hollow plasma generation electrode having one or more hollow discharge generation regions is arranged in the plasma generation region. Plasma is generated by the plasma generating means in a casing having a plasma generating means, a raw material gas inlet, and a substrate support table to turn the source gas into plasma, and the surface of the substrate placed on the substrate support table is converted into plasma. A surface treatment apparatus for treating,
In the casing, an anode electrode having one or more plasma outlets between a plasma generation region provided with the plasma generating means and a substrate processing region provided with the substrate support is spaced apart from an inner wall surface of the casing. And
At least one of the anode electrodes has one or more hollow discharge generation regions;
The surface treatment apparatus according to claim 1, wherein a hollow plasma generation electrode having one or more hollow discharge generation regions is arranged in the plasma generation region. The opening width W (1) of the minimum portion of at least one of the plasma outlets is set in a range satisfying either W (1) ≦ 5L (e) or W (1) ≦ 20X. The surface treatment apparatus in any one of -3.
However, L (e): the atom or molecular species having the smallest diameter among the source gas species and the electrically neutral atoms and molecular species (active species) generated by decomposition under the desired plasma generation conditions (active) Electron mean free path X with respect to the species): thickness of sheath layer generated under desired plasma generation conditions The said hollow plasma generation electrode has one or more recessed parts in the surface facing plasma generated by the plasma generating means, and at least one said recessed part is made into the said hollow discharge generation | occurrence | production area. Surface treatment equipment. The hollow plasma generating electrode is a hollow body, and the electrode has at least one through hole communicating with the inside of the cavity at a portion facing the plasma generated by the plasma generating means. The surface treatment apparatus of Claim 2 or 3 made into the said hollow discharge generation | occurrence | production area. The opening width W (2) of the minimum portion in the recess or the through hole is set in a range satisfying either W (2) ≦ 5L (e) or W (2) ≦ 20X. 6. The surface treatment apparatus according to 6.
However, L (e): the atom or molecular species having the smallest diameter among the source gas species and the electrically neutral atoms and molecular species (active species) generated by decomposition under the desired plasma generation conditions (active) Electron mean free path X with respect to the species): thickness of sheath layer generated under desired plasma generation conditions The hollow plasma generating electrode is a hollow body, and the electrode has one or more through holes communicating with the inside of the cavity at a portion facing the plasma generated by the plasma generating means, and at least a part of the inside of the cavity is formed. The surface treatment apparatus according to claim 2, 3, or 6, which is a generation area of hollow discharge. The facing distance H in at least a part of the inside of the cavity along the through hole formation direction of the hollow plasma generating electrode is set in a range satisfying either H ≦ 5L (e) or H ≦ 20X. Item 9. The surface treatment apparatus according to Item 8.
However, L (e): the atom or molecular species having the smallest diameter among the source gas species and the electrically neutral atoms and molecular species (active species) generated by decomposition under the desired plasma generation conditions (active) Electron mean free path X with respect to the species): thickness of sheath layer generated under desired plasma generation conditions The surface treatment apparatus according to any one of claims 1 to 9, wherein a magnetic field is formed in the vicinity of the plasma outlet and / or in the vicinity of the concave portion, the through hole, and / or in the cavity. The surface treatment apparatus according to claim 1, further comprising a potential applying means for applying a desired potential to the substrate.

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